Sure, it probably won't hurt -- but many search engines now just look at keywords and description AND title and most importantly relevancy to what's in your pages. A cool service at http://www.northernwebs.com/set/setsimjr.html(I think that's the address) gives you keyword and description analysis for free. Good luck!
Webmaster is right. More of the engines are putting weight on the 1st words on the page especially if they are in an H1 or H2 font. My guess is that since so many try to
fool the engines with Meta tags, they find that the Headline text of the site is more revelant and respresentative of the actual site content.
Google which now provides Yahoo's secondary search results uses the 1st text it finds on the page as your description NOT your description in your Meta tags.